My Angel of Music is Who?

It has been sixteen months since the final battle. Hogwarts is about to reopen but the Ministry made Headmistress McGonagall promise to make some changes to the curriculum. But the Headmistress doesn't know everything the Ministry has planned for the students and professors or the craziness that will ensue because of the new Muggle-Relations project. AU. OOC. Sorry no lemons.